JP3140062B2 - Control device for triggering fixed restraint safety means in a vehicle during a side collision - Google Patents

Description

The present invention relates to a control device for triggering a fixed safety device in a vehicle in the event of a side collision according to the preamble of claim 1.

Control devices for triggering a restraint-locked safety device in the event of a frontal or oblique impact are well known and are used in mass production in motor vehicles. An acceleration sensor having sensitivity in the direction of the vehicle longitudinal axis detects a negative acceleration of the vehicle caused by a frontal or oblique impact. The trigger circuit processes the acceleration signal according to an algorithm, and in the simplest case of the algorithm compares the amplitude of the acceleration signal with a limit value and, optionally, a driver- and passenger-airbag or Trigger a restraint safety device such as a seat belt. Due to the large distance between the collision location and the passenger occupied small space-cell and the energy absorption of the crash zone of the vehicle, a relatively long period of time can be allowed until the triggering of the restraint fixed safety means by the control device, Such a relatively long period can be tolerated. During this period, the time is used for evaluating the acceleration signal. Information about the severity, intensity and type and type of impact can be obtained by evaluating the post-phase of the acceleration signal, i.e., here the post-acceleration signal whose acceleration signal also reaches its maximum value. It can be obtained by evaluating phases.

In the case of a side impact, based on the configuration of the collision location, the small space between the location and the passenger-occupied small space-the cell and the crash zone, only a moderate energy absorption, up to the trigger decision-determination by the control unit Only very short time intervals of a few milliseconds must elapse. The acceleration signal caused by a collision transverse to the longitudinal axis of the vehicle is located within said short time during its climb phase. The acceleration signal reaches its maximum amplitude only in a predetermined post-phase and, in order to be able to still effectively protect the passenger in said predetermined post-phase, a trigger decision-decision must have already been made. You have to. Heretofore, therefore, lateral acceleration sensors have been provided for detecting lateral acceleration at the side of the vehicle, for example at the door, of which the first, but not the trigger determination, has been determined. -
A weak acceleration signal is detected in the phase near the potential side impact point. An acceleration sensor for detecting lateral acceleration, which is arranged in the central region of the vehicle, sends out an excessively weak acceleration signal at least in its first phase, based on the damping by the vehicle body, so that a reliable trigger determination can be made. The conclusion of the decision cannot be derived. If the limit value is necessarily set too low as a trigger limit value under a weak acceleration signal, an undesired triggering can be caused by a slight fluctuation of the acceleration signal or a disturbance signal. As a result, it has heretofore seemed impossible to arrange a trigger circuit and an acceleration sensor for triggering the restraint-fixed safety means in the event of a side collision in the central control device.

Frontal or oblique impacts pose a further problem in previously known controls for triggering a restraint-type safety device in the event of a side impact. Each frontal or oblique impact also causes a transverse acceleration with respect to the longitudinal axis of the vehicle, which transverse acceleration is advantageously of high amplitude during the subsequent phase of the frontal or oblique impact; May be provided. Such lateral acceleration triggers a fixed security device to protect against side impacts.
In the case of a side collision with the lateral acceleration, a trigger is preferable, but in the case of a frontal or oblique collision, the trigger is not preferable.

Paper “New Sensor Concepts for Reliable De
tection of Side- Impact Collisions "
International technical Conference of Enhanced
Safety of Vehicles, Proceedings No. 1035-1038
page. Has a pneumatic sensor at the vehicle door, which detects the increase in air pressure that occurs during a side collision at the vehicle door as a measure or indicator for the acceleration of the vehicle based on the side collision. The pneumatic sensor is connected to a trigger circuit provided in the central area of the vehicle, which triggers a fixedly secured safety means, for example a side or side airbag, in the event of a sufficiently strong side collision.

Such a control device with decentralized, decentralized sensors has the following components, together with the line and the plug connector between the trigger circuit and the sensor: There are components that require significant cost to check for gender. Furthermore, such controllers require high production, assembly, replacement and repair costs.

The control device according to the generic concept of claim 1 is DE422259
Known from 5A1. The control device has two acceleration sensors mounted on the vehicle and arranged at 90 degrees to each other, so that the sensor device has a longitudinal direction for acceleration in a direction parallel to the vehicle longitudinal axis. An acceleration signal and a transverse acceleration signal for an acceleration transverse to the longitudinal axis of the vehicle are transmitted. An acceleration vector is calculated from the above-mentioned amount acceleration signal by a trigger circuit, and the acceleration vector is determined by its magnitude and an angle with respect to the vehicle longitudinal axis. Depending on the acceleration vector, a fixed security device, for example a side or side airbag, is selected from a number of fixed security devices provided in the vehicle and triggered.

From the article "Point to Poinnt" Norman Martin, "Automotive Industries", Juli 1993, pp. 49-51, a control device for triggering a restraint-type safety device in a vehicle in the event of a forward collision is known. For this purpose, two acceleration sensors are arranged together with the trigger circuit in a common control unit at an angle of +/- 45 degrees with respect to the longitudinal axis of the vehicle. Depending on the acceleration signal, the restraint-locked safety means is triggered.

WO 89/11986 discloses a control device for triggering a restraint-type safety device in a vehicle in the event of a frontal or oblique impact. The control device has two acceleration sensors that are offset from each other by 90 degrees. The sensor device emits a longitudinal acceleration signal of an acceleration parallel to the vehicle longitudinal axis and a transverse acceleration signal of an acceleration transverse to the vehicle longitudinal axis. The acceleration signal is evaluated, on the one hand, in an analog circuit and, on the other hand, in a microprocessor and controls the restraint-locked safety means (as long as a frontal or oblique impact is identified as such).

The problem underlying the present invention is to ensure timely triggering of the restraint-locked safety means in the event of a sufficiently strong side impact and, at the same time, a relatively weak side impact or frontal or oblique direction. An object of the present invention is to provide a compact control device in which a trigger in the case of a directional collision is prevented.

The above object is achieved by the features described in claim 1. The sensor device having two acceleration sensors and the trigger circuit are arranged in the same control device. The timely triggering of the restraint-locked safety device in the event of a side collision is ensured in the following way: the sensor device has two acceleration sensors and is parallel to the vehicle longitudinal axis. A longitudinal acceleration signal for directional acceleration and a lateral acceleration signal for acceleration transverse to the vehicle longitudinal axis. The trigger circuit, of course,
A first signal dependent on the lateral acceleration and a second signal dependent on the longitudinal acceleration are used. The output signals dependent on the longitudinal and lateral acceleration signals delivered by the trigger circuit are compared to a limit value, and if the limit value is exceeded, the restraint-locked safety means is triggered.

Trials have shown that when a vehicle undergoes a longitudinal acceleration based on a side impact, the amplitude of the longitudinal acceleration is much smaller than the amplitude of the lateral acceleration in the case of a side impact. However, the above-mentioned lateral acceleration is always, especially during the first phase of the side impact,
It exists. If the above longitudinal acceleration signals are considered together in the output signal delivered by the trigger circuit, a reliable trigger-determination-decision can be made. To this end, the output signal is a first signal dependent on lateral acceleration.
It is determined by the quotient of the signal and the first signal depending on the longitudinal acceleration. The quotient thus has a significantly higher value, in particular in the first phase of the side impact, which triggers a reliable trigger-determination via a threshold value comparison. Furthermore, by taking into account the longitudinal acceleration signal in the output signal, the lateral acceleration signal caused by a frontal or oblique impact is also distinguished from the lateral acceleration signal caused by a side impact. The disadvantageous triggering of the restraint-locked safety means in the case of a frontal or oblique impact is avoided.

The control device of the present invention is compact, assembled in a small number of operating steps, and is easily maintained and replaced. The plug and terminal connectors between the distributed sensors, lines and trigger circuits are eliminated.

Advantageous developments of the invention are specified in the subclaims.

 Next, the present invention will be described with reference to the drawings.

FIG. 1 shows an arrangement configuration of a control device having a control device of the present invention in a vehicle.

 FIG. 2 is a block connection diagram of the control device of the present invention.

FIG. 3 shows a diagram of the longitudinal and lateral accelerations that occur during a side impact of the vehicle within the first 10 ms after the onset and onset of the side impact.

FIG. 1 shows a vehicle having a control device 1, which has a control device 2 having a sensor device 3 and a trigger circuit 4. The ignition signal Z is transmitted from the control device 2 to the fixed-lock safety device 5 via the line. On the sensor device 3, the sensitivity axes of the two acceleration sensors are symbolically indicated. The first acceleration sensor sends out a longitudinal acceleration signal, and its sensitivity axis is the vehicle longitudinal A-
Extending parallel to A ', the second acceleration sensor emits a lateral acceleration signal, and its sensitivity axis extends transverse to the vehicle longitudinal direction AA'. The control device 1 is arranged in a central area of the vehicle.

FIG. 2 shows a block diagram of the control device 2 having a sensor device 34, which supplies a longitudinal acceleration signal y (t) to a trigger circuit. The trigger circuit 2 supplies an output signal a (t) to the comparator 41. Output signal a
If (t) exceeds the limit value G, the ignition signal Z is transmitted to the fixed safety device 5.

The sensor device 3 includes at least two acceleration signal sensors
32,32. The acceleration signal sensors are arbitrarily arranged spatially. Here, it is assumed that the sensor device 3 has a longitudinal acceleration signal corresponding to an acceleration in a direction parallel to the vehicle longitudinal direction AA ′. It is assumed that a lateral acceleration signal y (t) corresponding to x (t) and an acceleration transverse to the vehicle longitudinal direction AA 'is transmitted. Here, the acceleration signal sensors 31, 32 preferably have a sensitivity axis as follows, i.e. a sensitivity axis oriented parallel and transverse to the vehicle longitudinal direction AA '. Is also symbolically shown in FIG. However,
The arrangement of the acceleration signal sensors 31 and 32 at ± 45 degrees or other angles with respect to the vehicle longitudinal direction AA ′ is also possible. The longitudinal acceleration signal (x (t)) and the lateral acceleration (Y
(T)) is determined from the signals of the acceleration signal sensors 31, 32 via a corresponding angle function.

The acceleration signal sensors 31, 32 send out analog or quasi-analog signals. Here, the sensor may be capacitive, piezoresistive or operate in other manners and principles. Each acceleration signal may consist of different acceleration switches having different response limits, where:
The individual signals of the individual acceleration switches are combined into one quasi-analog acceleration signal.

Advantageously, the acceleration signal sensor 31 or 32 is bipolar,
The acceleration sensors are configured to be bipolar, that is, each acceleration sensor is sensitive and sensitive to two directions opposite to each other. Thereby, for example, the acceleration signal sensor 32 can identify the acceleration caused by a left and right collision with its sensitivity axis transverse to the vehicle longitudinal direction AA '.
Alternatively, unipolar, unipolar acceleration signals can also be used, it being assumed that the sensor device 3 comprises a vehicle longitudinal acceleration signal x (t) and a lateral acceleration signal y (t). ).

When the integrations 31 and 32 are used, the acceleration sensor can be manufactured together with the trigger circuit 4 on one semiconductor chip.

The trigger circuit 4 can be configured as an analog circuit or a microprocessor. The output signal a (t) delivered by the trigger circuit is compared with a limit value G, via which the sensitivity of the control device 2 is adjusted and set. If the output signal a (t) exceeds the limit value G, an ignition signal Z is supplied to at least one fixed-lock safety device 5. The restraint-type safety means are advantageously side or side airbags on the driver or passenger side or other means for protecting the passenger in the event of a side collision.

Advantageously, the output signal a (t) is compared with a plurality of different limit values to determine a plurality of fixedly secured safety means or a plurality of stages of a multi-staged fixedly secured safety means, for example one side or one side. The plurality of chambers and chambers of the side airbag may be triggered at different times depending on the strength of the side collision.

Advantageously, the trigger circuit 4 has a further circuit unit which, depending on the vehicle longitudinal acceleration signal x (t) and the lateral acceleration signal y (t), only has a fixed locking. Trigger only form safety measures.
Thus, for example, on the driver side, in the event of a side collision, the restraint-fixed safety means is triggered, and the restraint-fixed safety means is disposed on the driver side, and is restrained on the passenger side. Shaped safety measures are not triggered.

According to the invention, the trigger circuit 4 sends out an output signal a (t) which depends not only on the lateral acceleration y (t) but also on the vehicle longitudinal acceleration signal x (t). Dependent. FIG. 3 qualitatively shows the lateral and longitudinal accelerations X and Y acting on the vehicle during the first few milliseconds from the start of the side impact. Longitudinal acceleration signal x (t)
Is clearly recognizable and recognizable even in a side collision occurring at an angle of 90 degrees to the longitudinal direction AA 'of the vehicle, but produces a significantly weaker signal. The side collision is performed at an angle of 90 degrees with respect to the longitudinal direction AA 'of the vehicle. The lateral acceleration signal y (t) detected by the central sensor device 3 in the first few msec of the side collision is:
The lateral acceleration signal “door” y _t (t) is generated weaker than the lateral acceleration signal “door” y _t (t).
Is detected by an acceleration sensor arranged in the vehicle door.

The lateral acceleration signal y (t) is compared with a limit value, the lateral acceleration signal "door" y _t (t) which differ from reliable trigger determination - determination is not caused. The threshold value for a trigger decision-decision must necessarily be set very low. Thus, a slight fluctuation of one acceleration signal or even a disturbance signal can trigger another undesirable trigger.

Advantageously, the first dependent on the lateral acceleration signal y (t)
And the longitudinal acceleration signal x
(T) associated with the second signal. here,
The following facts are used: from the quotient of the first signal having a relatively small amplitude and the second signal having a significantly smaller amplitude, the output signal a having a significantly larger amplitude
(T) is delivered and the output signal is compared to a limit value G, thus giving a reliable trigger decision-decision. Here, the first signal that depends on the lateral acceleration signal is the dividend, and the second signal that depends on the longitudinal acceleration signal is the divisor. Furthermore, the lateral acceleration y (t) caused by a frontal or oblique impact never triggers the locking safety device 5, because the longitudinal acceleration in the denominator of the quotient. This is because as the signal x (t) increases, the value of the quotient decreases, and the output signal a (t) does not exceed the limit value G.

Advantageously, the first signal is an energy signal dependent on the lateral acceleration signal y (t) and the second signal is an energy signal dependent on the longitudinal acceleration signal x (t). Here, the energy signal represents the temporal energy reduction of the energy transmitted to the vehicle by the side impact in the longitudinal or lateral direction since the start of the side impact. The use of the energy signal increases the signal spacing between the first signal and the second signal, and hence the amplitude of the quotient; thus, the limit determination becomes more reliable. High-frequency fluctuations of the acceleration signal are smoothed by the temporal addition of the differential or differential energy contribution. Furthermore, the temporal history of the acceleration signal is taken into account.

Advantageously, the first signal has an additive constant and the second signal has an additive constant K2. Via the constants K1, K2 and the limit value G, the trigger decision-making is adapted to the respective application or the respective vehicle type.

Advantageously, the output signal a (t) is calculated by the following relation:

The trigger circuit 4 may be an arbitrary arrangement of the acceleration sensor in the sensor device 31 or may be a microprocessor, and may be arranged together with the sensor device 3 in the same control device 1 in the central region of the vehicle.

The sensor device 3 disposed at the center includes the acceleration sensors 31 and 3
The longitudinal acceleration signal x under any given configuration
The following signals are transmitted together with (t) and the lateral acceleration signal y (t), that is to say a signal which can also be used for frontal or oblique collision discrimination based on the evaluation by the trigger circuit.

Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B60R 21/16-21/32 PCI (DIALOG)

Claims (8)

(57) [Claims] 1. A control device for triggering a restraint fixed type safety means in a vehicle in the event of a side collision, comprising a sensor device (3), the sensor device comprising two acceleration sensors (31, 32). ) And the vehicle longitudinal axis (A
-A ') and a longitudinal acceleration signal (x (t)) for acceleration in a direction parallel to the vehicle longitudinal axis (A-).
A ′) for transmitting a transverse acceleration signal (y (t)) corresponding to a transverse acceleration, and has a trigger circuit (4). (T)) and an output signal (a (t)) determined by the lateral acceleration (y (t)), where the output signal (a (t)) is equal to the limit value (G). If so, wherein the restraint-locked safety means (5) is arranged to be triggered, wherein the output signal (a (t)) is the lateral acceleration signal (y
(T)) and a second signal that depends on the longitudinal acceleration signal (x (t)). The dependent first signal is the dividend, the second signal dependent on the longitudinal acceleration signal is the divisor, and the quotient of the lateral acceleration signal and the longitudinal acceleration signal is an occupant that is initially set. A control device for triggering a restraint-type safety device in a vehicle in the event of a side collision, wherein the control device is adapted to be used for triggering a protection device. 2. The first signal is a lateral acceleration signal (y (t)).
2. The apparatus according to claim 1, wherein the second signal is determined by an energy signal dependent on the longitudinal acceleration signal (x (t)). 3. The output signal is calculated by the following equation: Where the meanings of the symbols of the variables in the formula are as follows: a (t) output signal y (t) lateral acceleration signal x (t) longitudinal acceleration signal K1 constant K2 constant An apparatus according to claim 1. 4. The device according to claim 1, wherein the control device is provided in a central area of the vehicle. 5. The device according to claim 1, wherein each of the acceleration sensors is sensitive and sensitive to two directions opposite to each other. 6. The first acceleration sensor (31) is connected to a vehicle longitudinal axis (A).
-A '), and the second acceleration sensor (32) has a sensitivity axis transverse to the vehicle longitudinal axis (A-A'). Claim 1
The described device. 7. The device according to claim 1, wherein the trigger circuit is a microprocessor. 8. The device according to claim 1, wherein the device is simultaneously used in a vehicle to trigger a restraint safety device in frontal and oblique collisions.